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Aluminum 6XXX alloys show high strength to weight ratios and are thus promising materials for today’s transport industry lightweight construction efforts. When considering both deformation and final mechanical properties, high ductility is interesting from the conformability point of view. On the other hand, high resistance is necessary in the automotive structural parts (which can be obtained through T6 precipitation heat treatment) but leads to reduced ductility. In order to increase aluminum alloys’ formability, warm forming is commonly applied. In contradiction to this, this article shows how the tensile deformation behavior of the 6082 T6 alloy is not affected by the temperature. In this work, the necessary formability values to obtain the parts are achieved, deforming the material under O annealed condition. But this strategy is focused on the formability perspective; therefore, the final mechanical properties do not achieve the necessary strength requirements. As a solution, the possibility of applying the T6 heat treatment after forming the parts (in annealed condition) is studied. A tensile characterization of the post-heat-treated specimens obtained from the deformed experimental part results in high flow stress levels, and thus, the strategy is validated. Nevertheless, the heat treatment leads to geometrical distortions in the final part, and thus, a last calibration step should be added to the forming process in order to obtain the desired shape.

Laser-induced periodic surface structures (LIPSS, ripples) with ~500–700 nm period were produced on titanium alloy (Ti6Al4V) surfaces upon scan processing in air by a Ti:sapphire femtosecond laser. The tribological performance of the surfaces were qualified in linear reciprocating sliding tribological tests against balls made of different materials using different oil-based lubricants. The corresponding wear tracks were characterized by optical and scanning electron microscopy and confocal profilometry. Extending our previous work, we studied the admixture of the additive 2-ethylhexyl-zinc-dithiophosphate to a base oil containing only anti-oxidants and temperature stabilizers. The presence of this additive along with the variation of the chemical composition of the counterbodies allows us to explore the synergy of the additive with the laser-oxidized nanostructures.

Abstract. Although the effect of surface topography on fatigue life is widely accepted, the underlying role of surface roughness from first principles is still poorly understood. Currently approaches which consider the influence of surface roughness on fatigue life prediction can be broadly classified into surface corrector factors (C s ) and stress concentration factors (K t ). Those approaches describe the surface according to the manufacturing process (machined, grounded…), or using 2D height descriptor parameters (R a , R z ...). However, these approaches are not able to correctly describe the effect of roughness on the fatigue performance where it is anticipated a richer set of surface descriptors would show correlation. The present work aims to highlight the inherent limitations of the most commonly employed 2D surface measurement and characterization techniques, and provides an insight into the application of 3D areal surface characterization processes including the use of the latest areal surface topography parameters quantifying amplitude, spatial, and hybrid topographical information which is considered to be important for fatigue performance correlation.

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